Here, the electrophotographic image forming apparatus forms an image on a recording material using an electrophotographic image formation type process. The electrophotographic image forming apparatus includes an electrophotographic copying machine, an electrophotographic printer (laser beam printer, LED printer, for example), a facsimile machine, a word processor, a complex machine having a plurality of functions thereof and so on.
A developer is powder and may be one component toner, two-component toner, or a mixture of the two-component toner and a carrier.
Conventionally, a fine particle developer is used in the electrophotographic image forming apparatus such as the electrophotographic copying machine, printer or the like. When the developer of a main assembly of the electrophotographic image forming apparatus is consumed, the developer is supplied into the main assembly of the image forming apparatus using a developer supply container.
The developer is extremely fine powder, and therefore, in order to prevent scattering of the developer during exchanging operation for the developer supply, the developer is stably discharged using the air through a small opening, as is known.
For example, in a supplying type disclosed in Japanese Laid-open Patent Application 2010-256894, a pump portion capable of raising and reducing the pressure in the developer supply container relative to the ambient air by a drive received from the image forming apparatus is provided, so that the air is taken in the container and then the developer is discharged through a discharge opening.